As piezoelectric actuators, there are known a device which employs a bimorph-type piezoelectric element constructed by forming a surface electrode on a surface of a staked body in which a plurality of internal electrodes and piezoelectric layers are laminated (refer to Patent Literature 1) and a device constructed by joining a piezoelectric element and a flexible substrate together in a manner such that a surface electrode of the piezoelectric element and a wiring conductor of the flexible substrate are electrically connected to each other (refer to Patent Literature 2).